Artificial destratification for reducing reservoir water evaporation

Is it effective?

Fernanda Helfer, Fernando P. Andutta, José A. Louzada, Hong Zhang, Charles Lemckert

Research output: Contribution to journalArticle

Abstract

The objective of the present study was to assess the effectiveness of artificial destratification by air-bubble plumes in reducing evaporation from reservoirs. The model DYRESM was used to model the evaporation rates and thermodynamic behaviour of a temperate reservoir in Australia under a number of combinations of destratification designs and operating conditions, comprising various numbers of ports and air-flow rates per port. The operating conditions involved continuous operation and various intermittent operating strategies. Three reservoir depths were considered, characterizing “shallow,” “medium” and “deep” reservoirs, respectively. The present study results indicated that, assuming thermal stratification develops in a reservoir (the case for the “medium” and “deep” reservoirs), artificial destratification is able to reduce surface temperatures and evaporation rates. As a result of the larger volume of cold water at the lake bottom, deeper reservoirs can derive greater benefit from the use of these systems. Being raised to the water surface by the air injected through the destratification system, the cold water from the bottom will help reduce surface temperatures. Conversely, because of their typical homothermous regime, shallow lakes are unlikely to benefit from these systems, since these reservoirs lack an abundant cold water source at the bottom. Even so, however, the reductions in evaporation from deep reservoirs are only modest, with the maximum reduction being only 2.9% for a deep lake (16.5 m) using an energy-intensive destratification system. Based on the present study, it was concluded that using destratification systems for reducing reservoir evaporation was not warranted because of the modest water savings achieved.

Original languageEnglish
Pages (from-to)333-350
Number of pages18
JournalLakes and Reservoirs: Research and Management
Volume23
Issue number4
DOIs
Publication statusPublished - 1 Dec 2018

Fingerprint

evaporation
cold water
lake
surface temperature
water reservoir
air bubble
airflow
stratification
plume
thermodynamics
surface water
air
energy
rate

Cite this

Helfer, Fernanda ; Andutta, Fernando P. ; Louzada, José A. ; Zhang, Hong ; Lemckert, Charles. / Artificial destratification for reducing reservoir water evaporation : Is it effective?. In: Lakes and Reservoirs: Research and Management. 2018 ; Vol. 23, No. 4. pp. 333-350.
@article{b83f292174914165bfa1560afde80c8e,
title = "Artificial destratification for reducing reservoir water evaporation: Is it effective?",
abstract = "The objective of the present study was to assess the effectiveness of artificial destratification by air-bubble plumes in reducing evaporation from reservoirs. The model DYRESM was used to model the evaporation rates and thermodynamic behaviour of a temperate reservoir in Australia under a number of combinations of destratification designs and operating conditions, comprising various numbers of ports and air-flow rates per port. The operating conditions involved continuous operation and various intermittent operating strategies. Three reservoir depths were considered, characterizing “shallow,” “medium” and “deep” reservoirs, respectively. The present study results indicated that, assuming thermal stratification develops in a reservoir (the case for the “medium” and “deep” reservoirs), artificial destratification is able to reduce surface temperatures and evaporation rates. As a result of the larger volume of cold water at the lake bottom, deeper reservoirs can derive greater benefit from the use of these systems. Being raised to the water surface by the air injected through the destratification system, the cold water from the bottom will help reduce surface temperatures. Conversely, because of their typical homothermous regime, shallow lakes are unlikely to benefit from these systems, since these reservoirs lack an abundant cold water source at the bottom. Even so, however, the reductions in evaporation from deep reservoirs are only modest, with the maximum reduction being only 2.9{\%} for a deep lake (16.5 m) using an energy-intensive destratification system. Based on the present study, it was concluded that using destratification systems for reducing reservoir evaporation was not warranted because of the modest water savings achieved.",
keywords = "air-bubble plumes, DYRESM, lake, modelling and simulation, water balance, water temperature",
author = "Fernanda Helfer and Andutta, {Fernando P.} and Louzada, {Jos{\'e} A.} and Hong Zhang and Charles Lemckert",
year = "2018",
month = "12",
day = "1",
doi = "10.1111/lre.12241",
language = "English",
volume = "23",
pages = "333--350",
journal = "Lakes Reservoirs: Research and Management",
issn = "1320-5331",
publisher = "Wiley-Blackwell",
number = "4",

}

Artificial destratification for reducing reservoir water evaporation : Is it effective? / Helfer, Fernanda; Andutta, Fernando P.; Louzada, José A.; Zhang, Hong; Lemckert, Charles.

In: Lakes and Reservoirs: Research and Management, Vol. 23, No. 4, 01.12.2018, p. 333-350.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Artificial destratification for reducing reservoir water evaporation

T2 - Is it effective?

AU - Helfer, Fernanda

AU - Andutta, Fernando P.

AU - Louzada, José A.

AU - Zhang, Hong

AU - Lemckert, Charles

PY - 2018/12/1

Y1 - 2018/12/1

N2 - The objective of the present study was to assess the effectiveness of artificial destratification by air-bubble plumes in reducing evaporation from reservoirs. The model DYRESM was used to model the evaporation rates and thermodynamic behaviour of a temperate reservoir in Australia under a number of combinations of destratification designs and operating conditions, comprising various numbers of ports and air-flow rates per port. The operating conditions involved continuous operation and various intermittent operating strategies. Three reservoir depths were considered, characterizing “shallow,” “medium” and “deep” reservoirs, respectively. The present study results indicated that, assuming thermal stratification develops in a reservoir (the case for the “medium” and “deep” reservoirs), artificial destratification is able to reduce surface temperatures and evaporation rates. As a result of the larger volume of cold water at the lake bottom, deeper reservoirs can derive greater benefit from the use of these systems. Being raised to the water surface by the air injected through the destratification system, the cold water from the bottom will help reduce surface temperatures. Conversely, because of their typical homothermous regime, shallow lakes are unlikely to benefit from these systems, since these reservoirs lack an abundant cold water source at the bottom. Even so, however, the reductions in evaporation from deep reservoirs are only modest, with the maximum reduction being only 2.9% for a deep lake (16.5 m) using an energy-intensive destratification system. Based on the present study, it was concluded that using destratification systems for reducing reservoir evaporation was not warranted because of the modest water savings achieved.

AB - The objective of the present study was to assess the effectiveness of artificial destratification by air-bubble plumes in reducing evaporation from reservoirs. The model DYRESM was used to model the evaporation rates and thermodynamic behaviour of a temperate reservoir in Australia under a number of combinations of destratification designs and operating conditions, comprising various numbers of ports and air-flow rates per port. The operating conditions involved continuous operation and various intermittent operating strategies. Three reservoir depths were considered, characterizing “shallow,” “medium” and “deep” reservoirs, respectively. The present study results indicated that, assuming thermal stratification develops in a reservoir (the case for the “medium” and “deep” reservoirs), artificial destratification is able to reduce surface temperatures and evaporation rates. As a result of the larger volume of cold water at the lake bottom, deeper reservoirs can derive greater benefit from the use of these systems. Being raised to the water surface by the air injected through the destratification system, the cold water from the bottom will help reduce surface temperatures. Conversely, because of their typical homothermous regime, shallow lakes are unlikely to benefit from these systems, since these reservoirs lack an abundant cold water source at the bottom. Even so, however, the reductions in evaporation from deep reservoirs are only modest, with the maximum reduction being only 2.9% for a deep lake (16.5 m) using an energy-intensive destratification system. Based on the present study, it was concluded that using destratification systems for reducing reservoir evaporation was not warranted because of the modest water savings achieved.

KW - air-bubble plumes

KW - DYRESM

KW - lake

KW - modelling and simulation

KW - water balance

KW - water temperature

UR - http://www.scopus.com/inward/record.url?scp=85054924454&partnerID=8YFLogxK

U2 - 10.1111/lre.12241

DO - 10.1111/lre.12241

M3 - Article

VL - 23

SP - 333

EP - 350

JO - Lakes Reservoirs: Research and Management

JF - Lakes Reservoirs: Research and Management

SN - 1320-5331

IS - 4

ER -